* {
    margin: 0;
    padding: 0;
}

li {
    list-style: none;
}

body,
html {
    height: 100%;
}

html {
    font-size: 100px;
}

body {
    font-size: 16px;
}


/* 头部 */

.zfb {
    height: 100%;
    display: flex;
    flex-direction: column;
}

header {
    /* 
        逻辑像素 = 物理像素 / 像素比
        逻辑像素 = 310 / 2 = 155px
        用rem作为单位
        ？ = 155 / 100 = 1.55rem
    */
    height: 1.55rem;
    background-color: #3f454f;
    display: flex;
    flex-direction: column;
}

header .top {
    flex: 1;
    display: flex;
    align-items: center;
    padding: 0 0.16rem;
}

header .top span:nth-child(1) {
    flex: 5;
}

header .top span {
    flex: 1;
    color: #ffffff;
    font-size: 20px;
}

header .top span i {
    font-size: 20px;
    vertical-align: middle;
}

header .top span span {
    font-size: 12px;
    vertical-align: middle;
}

header .bottom {
    flex: 3;
    display: flex;
    justify-content: space-around;
    align-items: center;
    color: #ffffff;
}

header .bottom li {
    display: flex;
    flex-direction: column;
    align-items: center;
}

header .bottom li i {
    font-size: 40px;
}

header .bottom li span {
    font-size: 15px;
    margin-top: 0.12rem;
}


/* 内容 */

main {
    flex: 1;
    margin-top: 4px;
}

main .nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

main .nav li {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 0.93rem;
    height: 0.9rem;
    border: 1px solid #cccccc;
}

main .nav li {
    border-left: none;
    border-bottom: none;
}

main .nav li:nth-child(4n) {
    border-right: none;
}

main .nav li:nth-last-of-type(1) {
    border-bottom: 1px solid #cccccc;
}

main .nav li:nth-last-of-type(2) {
    border-bottom: 1px solid #cccccc;
}

main .nav li:nth-last-of-type(3) {
    border-bottom: 1px solid #cccccc;
}

main .nav li:nth-last-of-type(4) {
    border-bottom: 1px solid #cccccc;
}

main .nav li i {
    font-size: 26px;
}

main .nav li span {
    font-size: 12px;
    margin-top: 13px;
}

footer {
    height: 0.5rem;
}

footer .icon {
    display: flex;
    justify-content: space-around;
    height: 100%;
    /* color: #ffffff; */
}

footer .icon li {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-around;
}

footer .icon li i {
    font-size: 22px;
}

footer .icon li span {
    font-size: 12px;
}